View Full Version : Body Fat/Weight scale

03-04-2003, 02:27 AM

I have been using my body fat weight scale for some time now. I have read some posts here where people say to take your body fat first thing in the morning. The owner's manual, however, says that because of being deprived of water overnight, the bodyfat reading will not be accurate first thing in the morning and that you should take it in the evening preferably after supper. When is the best time of the day to get a consistently accurate reading?

03-04-2003, 02:09 PM
The bloating towards the end of the day is water. I put on a pound or two towards the end of the day. I don't think I would want that to be calculated as BF when it is BF and water. So if you want to get the true BF then so it in the morning, just as you would weigh yourself in the morning too. That's what I would do anyway.

03-04-2003, 03:37 PM
I agree......do any type of BF measurements first thing in the morning.

03-04-2003, 03:51 PM
Actually if you are using an impedance device I don't think it matters, so much as you take the reading at the same time every time. My scale underestimates my bf by about 2%, but the drift is +/- 2% depending on hydration. In other words I've seen the instrument be dead-on, but as high as 4% over, with the average being 2% off over the course of a month where I was "maintaining" using a 7-point caliper test as the calibration.

So to me the important reason for using it is not quantitative but qualitative, ie am I gaining or losing bf. Graph it over the course of a week/month. I take the reading at night just before going to bed but after "relieving" myself. The readings in the morning are off by a greater amount, on average, even though the drift is less- it's more consistent, but more consistently wrong.

03-04-2003, 04:28 PM
I have a tanita scale . The hydration they refer to is of course water in the body . As we sleep we lose water and therefore the resistance through our bodies rises and shows on the scale as higher fat % . That is why they don't recommend morning testing . During the day as we drink and rehydrate the resistance reduces and the % becomes more accurate . I usually test when I come home from work before supper .
I say "more accurate" with tongue in cheek because my BF calipers show vastly lower readings than the scale no matter how much water I have consumed . I must confess I do not have the "athletic" version of the scale and I uderstand they give far closer readings when you are in shape . I should have read the small print when I bought them as I had no idea why it made a difference at the time and either did the salesman .

03-04-2003, 04:36 PM
I also have a Tanita, and my experience is similar to back2it's. You are usually more dehydrated first thing in the morning. I have both athlete & regular mode on my scale. Not sure which one is more accurate for me.

03-04-2003, 04:47 PM
I was just reading my instructions on my Taylor scale and it says that it can be used any time of day...as long as it is the same time everytime you use it. It says that it is not affected my water retention levels as other BF analyzers are.

So I guess whatever the instructions are with the scale you are using is the way to go.

03-04-2003, 04:49 PM
well I'd imagine being consistent with the measurement is better, though I cannot for the life of me think why taking them consistently in the morning is less consistent than in the evening since in the morning your bound to be getting more consistency than taking it in the evenings when you have consumed different amounts of food and drink from one day to the next. Whereas in the morning, everything should be more of a same old same old.

If I did measure body fat that way, since I've learned that fat cells absorb fluid and swell during the day like muscle cells do, I'd rather take it in the morning when they are low on water and containing mostly fat after fasting for 8 hours. Seems to me that you'll get a more accurate reading of what the fat actually is in your body there. Irregardless as to what time you measure, always measure at the same time of day, because if you differ too much from that, you WILL see vast differences in what your body fat percentage is when half the time it's only water retention differences towards the end of the day.

I'd rather measure in the morning because there is at that time been nothing any different done for the past 8 hours whereas in the afternoon if you took it----did you do exactly the same as you did the week before when you took it for 8 hours i.e. drink and food wise? The measurement is more likely therefore to be different where hydration levels are concerned. The chances are you did the same are a lot less than they are in the morning when all you did was sleep for 8-9 hours and not eat or drink and depkleted your body to exactly the same levels where hydration is concerned. Which renders you to the same state each morning really. Even if you drank fluid before going to bed and ate a large meal, you'd be up in the night peeing it away and still be having the same fluid levels you had when you took it the week before in the morning.